1. Field
Embodiments of the present disclosure relate to an air conditioner which prevents a failure due to a line connection error between devices and saves standby power.
2. Description of the Related Art
An air conditioner is an apparatus which cools, heats or purifies sucked air using heat movement occurring during compression, condensation, expansion and evaporation processes of a refrigerant, and then discharges the air to condition air of a specific indoor space.
Such an air conditioner includes a compressor compressing the refrigerant into a high-temperature and high-pressure state, a condenser condensing the refrigerant in the high-temperature and high-pressure state supplied from the compressor into a low-temperature and high-pressure liquid state through heat exchange with surrounding air, an expansion valve (or a capillary tube) decompressing the refrigerant in the low-temperature and high-pressure liquid state supplied from the condenser into a low-temperature and low-pressure liquid or gaseous state, an evaporator passing and evaporating the refrigerant in the low-temperature and low-pressure state supplied from the expansion valve to rob of surrounding heat to maintain a low external temperature, an air blower fan discharging the air cooled by the evaporator to the indoor space, and an accumulator filtering the refrigerant in the liquid state from among the refrigerant evaporated by the evaporator and causing the filtered refrigerant to be introduced back into the compressor.
The compressor and the condenser are located within an outdoor unit, the evaporator and the air blower fan are located within an indoor unit, and the indoor unit and the outdoor unit perform operation according to a command from a controller.
The controller is generally a wireless remote controller, but may be a wired controller due to a possibility of losing the wireless remote controller in case of a multi-air conditioner respectively conditioning air in a plurality of indoor spaces.
Two power lines and two communication lines are connected between the indoor unit and the outdoor unit of the air conditioner and between the indoor unit and the wired controller of the air conditioner. The indoor unit and the outdoor unit of the air conditioner, or the indoor unit and the wired controller of the air conditioner transmit and receive power through the two power lines and perform mutual communication based on a designated communication protocol through the two communication lines.
An installer needs to connect the two power lines and the two communication lines between the indoor unit and the outdoor unit when the indoor unit and the outdoor unit are installed, and needs to connect the two power lines and the two communication lines between the indoor unit and the wired controller when the wired controller is installed.
Therefore, the probability of occurrence of a line connection error between the power lines and the communication lines when the air conditioner is installed is high, the probability of occurrence of a failure of a communication circuit is high, and repair costs arise when the communication circuit failure occurs.
Particularly, as the numbers of outdoor units and indoor units in a multi-air conditioner increase, connection between communication lines and power lines is complicated and installation of the air conditioner is not easy.
Therefore, the communication circuit failure due to the line connection error is prevented by installing relays at communication terminals of communication circuits of the indoor unit and the outdoor unit such that the relay is turned on when the communication lines are normally connected and is turned off when a line connection error occurs due to connection of the power lines. Even if a line connection error between the communication lines and the power lines between the devices occurs, a part failure does not occur, and thus line connection between devices is facilitated.
However, since the relay needs to maintain the on state to achieve communication between the devices even in a standby mode, standby power is not saved.
Particularly, an air conditioner in a type in which power is applied to an outdoor unit consumes the same amount of power as in a general mode to receive a user command input to an indoor unit in the standby mode in which power of the outdoor unit is blocked.
Further, if the relay is turned off to minimize standby power in the standby mode, the communication lines may be cut off, communication signals from other devices may not be received, and thus the standby mode may not be released.